Process for the manufacture of shaped articles from regenerated cellulose



United States Patent 3,234,036 PROCESS FOR THE MANUFACTURE OF SHAPED ARTICLES FROM REGENERATED CELLULOSE Hanswilli von Brachel, Cologne-Snlz, and Heinz Dietrich Jordan, Leverkusen, Germany, assignors to Farbenfabriken Bayer Aktiengesellschatt, Leverkusen, Germany, a corporation of Germany No Drawing. Filed Oct. 24, 1962, Ser. No. 232,891 Claims priority, application Germany, Nov. 2, 1961,

4 Claims. (61. 106-465) The subject of the present invention is a process for the production of fibres, threads or films from regenerated cell-ulose, which are characterised by low swelling and high strength.

The higher demands recently made on such products in regard to their use for textile and technical purposes, in particular for their use .in tyre cord-s had led to a search for methods of suitably modifying the customary viscose process to obtain material of the desired properties.

Thus, methods are known in which so-called modifiers are added to the viscose or to the spinning bath in order to retard the xanthogenate decomposition and to reduce the gel swelling value, which frequently improves the properties of the spun threads. At the same time, the other spinning conditions also have had to be adapted to these altered conditions, for example it may be necessary to use higher concentrations oi zinc sulphate and lower concentrations of sulphuric acid in the precipitating bath or to use a separate second bath in which the necessary stretching of the resulting threads may be carried out.

Compound which are capable of producing the desired effects include numerous mono and poly-amines and their alkoxylated products and polyglycol ethers of various compositions or mixtures of the two classes of substances.

It is an object of the present invention to enable threads of low swellingand increased tensile strength and increased elongation to be produced by the viscose process. A further object of the invention consists in "ice agents such as those described in German patent specification 880,485 or in German Auslegeschritt 1,062,014.

The polyether sulphonium compounds used in accordance with the invention have the particular advantage providing novel additives for the viscose in the viscose I spinning process. Further objects of the invention will be clear from the following description and examples.

It has now been found that to achieve the above objects it is particularly advantageous to use polyether sulphonium compounds which are soluble at least to the extent of 0.1% in 5% sodium hydroxide solution and preferably have a molecular weight between 300 and 20,000. It is preferred to use those polyether sulphonium compounds in which the cation contains at least one ether oxygen atom or one sulphonium group for every 4 carbon atoms. The polyether sulphonium compounds are prepared by ternating polyether thioethers, the latter being obtainable by various methods. For example, the thioet-hers used as starting material may be prepared by oxal'kyl-ating mono-, dior polymercaptans or m0-no-, dior polythioether alcohols, by condensing dior polyhalogen alkyl-ethers with alkali metal sulphides or mono-, diand polymercaptans, by copolymerisation of alkylene sulphides with alkylene oxides or by mixed condensation of polyalkylene glycols with ,8- or v-hydroxyal-kyl sulphides. It is particularly advantageous to use the polyether thioethers which are described in French patent specification 1,201,171. The ternating of these polyether thioethers may be carried out with a large variety of alkylating agents, for example methyl iodide, allyl bromide, benzyl chloride, dimethyl sulphate, diethyl sulphate, triethyl phosphate, methylmcthane sulphonate, met-hyl-p-toluene-sulphonate or other alkylating that they are mixed homogeneously more easily with the viscose than the additive hitherto proposed, so that they are more effective. This also makes it possible to vary the other spinning conditions, particularly the nature of the viscose and the precipitating bath within wider limits than is possible with the use of many other modifiers, so that for example even when spinning ordinary commercial viscose in acid precipitating baths of the usual composition (i.e., baths having a higher concentration of sulphuric acid and sodium sulphate and lower concentration of zinc sulphate than indicated for the above-mentioned process) followed by stretching in air after the ordinary winding or centrifuging processes, a marked improvement in the qualities of the fibres may be obtained.

The compounds that may be used in accordance with the invention may very conveniently be applied by means of the dosing process used in spin dyeing, because when they have been injected in the form of their aqueous or alkaline solution into the main stream of the viscose and have passed through the mixing apparatus customarily provided in such plants, they are already uniformly distributed as required.

By this method, smaller proportions of modified viscous may be worked up without the necessity of having afterwards to clean extensive pipe systems, which is normally a very time-consuming process. Production is therefore more adaptable, for example because it is easier to transfer from.- one fibre type to another.

The substances incorporated in the viscose in accordance with the present invention can not only retard coagulation and thereby influence the formation of the threads in the viscose and in the spinning bath, but owing to their pronounced cationic character and their surface activity they can produce other effects which are advantageous for the spinning process. Examples of these include: improved filtering of the viscose, improved drawing of the threads, reduced tendency to block spinnerets and form incrustations, clarification of the spinning bath and the like. These features illustrate further advantages of these substances compared with-the non-ionic polyalkylene oxide compounds. In order to improve the spinning process in this sense, it has been customary for a long time to add so-cal'led spinning oils to the viscose. These are surf-ace active products of various types. The use of these spinning oils becomes superfluous in the method according to the invention.

The above described polyether sulphon-ium compounds may be added to the viscose in quantities which vary depending on the effect desired on the fibres and with the other conditions, the quantities varying between 0.1 and 4%, preferably 0.1 and 0.6% by weight.

The dosing process may be carried out with the usual apparatus without any additional equipment.

As already mentioned above, the production of fibres, threads and films of improved mechanical properties by the process according to the invention is not limited to particular compositions of viscose and of the spinning bath.

However, the precipitating baths preferably contain at least 3% by weight of zinc sulphate. The stretching of the spun threads, which is necessary in order to obtain good textile properties, may be carried out by known methods either in the spinning bath or in air or in special stretching baths.

The fibres and threads obtained with the use of the above mentioned viscose additives are distinguished from those prepared without the use of these additives by i u e having aflatteniadifieross-section, e. g., kidney shaped, reduced swelling and increased dry tensile strength and wet tensile strength without reduced elongation at break- The invention is further disclosed in the following examples which are illustrative but not limitative thereof.

. Example 1 A viscose containing 7.5% cellulose and 5.0% total alkali; and to which 2.25 g. of the compound described below has been added per kg. of viscose was spun at a degree of maturity corresponding to a saltpoint 8 from. a spinneret having 48 apertures of 90,11. diameter into an acid precipitating bath to form athread oh 180 total denier.

The bath contained-125 g./l. sulphuric acid, 250 g. /l.

sodium sulphateand 30 .g./-l. of zinc sulphate and the temperature of thebath was 45 C. After leavingrthe spinning bath,- in which it had traversed .50 cm.,' the The swelling value was reduced by 28% The drytensile strength was increased by 19% and the wettensile strength was increased by 25% and the elongation in the dry and the wet state were increased by 3% and 3.6% respectively.

This shows that the above mentioned viscose additives can considerably improve the mechanical prop: erties,

The. polyether sulphonium compound used in this example was prepared as follows:

600- g. of polyethylene glycol having a molecular 'weight of 600,200 g. of thiodiglycol and 8 g..pl1OS- phoric acid. were heated in a current'of CO at 185 C. until the. condensate had a hydroxyl number of 42.

Steam was then blown through the reaction product for. i 4 hours at 120 C. and 15 mm. Hg and the product was then dried for one hour at 120" C. and 15 mm. Hg and then slowly treatedwith 220 g. dimethylsulphate at product was heated for onemore hour at 95. 7

95 C. When the exothermic reactionhad ceased, the

Example 2 2 g. of the compound described below were added per kg. of viscose to a viscose with 7.2% cellulose and 4.8% alkali. The process was then continued as described in Example 1 except that a precipitating bath composed of 100 g./l. sulphuric acid, 230 g./l. sodium sulphate and 40 g./l. zinc sulphate at a temperature of.

50 C. wasused and only 2 rollers were used for stretching the thread 'by 100%.

o determining the textile. data and co p ri g them with those found in threads produced from viscose without additives, it was found thatthe swelling value was reduced by 35% and the dry .tensilestrength and wet tear strength was increased by 17% and 21% respectively.

The polyether polysulphonium. compound was pre- 1 pared. as in Example 1 except that instead ofusing polyethylene glycol with molecular weight 600, an equivalent. quantity of oxyethylated tripropylene glycol with molec,-.

ularweight 1200 was used.

Ex ample 3 Observing the same reaction conditions :as in Example 1 and using 1.5 g. per kg. of viscose of the compound described below, the threads differed from those pre pared-from unmodified. viscose as shown below:

Reduction in swelling: 24%; increase in dry tensile strength: 20%; increase inrwetstrengthr 22%.-

The polyether polysulphonium compound used was prepared as in Example 1 except that 1118 'polyether thio' ether had a hydroxyl number of 14 corresponding to a molecular weight of 8000.

We claim:

1. Viscose spinning solution whichcontains 01-40% by weight. of a polyether sulphoniu'm' compound containing one member ofthe groupjconsistingofa .sul-

ifonium group. for. every four OaIlbOrr atoms in the polymer chain, an ether group. for every four carbon atoms in the polymer chain, anda sulfoniurn group plus ether oxygen for every-four carbon atoms in the polymer chain, said compound being soluble at least to the extent.

of 0.1% in a 5% aqueous sodium hydroxide solution and having a molecular weight between 300 and 20,000.

2.:Viscose' spinning solution according to claim 1 which contains a polyether-sulphonium compound have ing in its cation at le-astone ether oxygen atom for every four carbon atoms. t

3. Viscose spinning solution according to claim '1 which contains'a polyether sulphonium compound havin its cation at least one sulfonium group for every four carbon atoms.

4..Viscose spinning solution containing 0.1 to 4.0-

weight 'percent of the iviscose of a polyethen sulfoniuin com-pound'having an average molecular weight ofifrom 300 to 20,000 and atleast one ether oxygen and sul-.

fonium group for every four carbon atoms,- saidpolyether sulionium' compound being soluble at least to an' extent of 0.1% in a 5.weight percent aqeuous sodium hydroxide solution.

References Cited by the; Examiner UNITED STATES PATENTS 3,116,353 12/1963 Brower 106165 3,151,194 9/1964 Van-Doornet a1. 106165,

FOREIGN PATENTS q 1,035,850 8/1959 Germany.

478,774 1/1938 1 Great @Britain.

MORRIS LIEBMAN, Primary Examiner. 

1.VISCOSE SPINNING SOLUTION WHICH CONTAINS 0.1-4.0% BY WEIGHT OF A POLYETHER SULPHONIUM COMPOUND CONTAINING ONE MEMBER OF THE GROUP CONSISTING OF A SULFONIUM GROUP FOR EVERY FOUR CARBON ATOMS IN THE POLYMER CHAIN, AN ETHER GROUP FOR EVERY FOUR CARBON ATOMS IN THE POLYMER CHAIN, AND A SULFONIUM GROUP PLUS ETHER OXYGEN FOR EVERY FOUR CARBON ATOMS IN THE POLYMER CHAIN, SAID COMPOUND BEING SOLUBLE AT LEAST TO THE EXTENT OF 0.1% IN A 5% AQUEOUS SODIUM HYDROXIDE SOLUTION AND HAVING A MOLECULAR WEIGHT BETWEEN 300 AND 20,000. 